World Data Center for Geomagnetism
The WDC has a FTP-server to distribute the definitive PCN index derived from the geomagnetic observatory Qaanaaq (THL) and the Kp-index data products derived at the geomagnetic observatory Niemegk (NGK).
The WDC is also holding extensive archives of magnetograms and other geomagnetic observatory data products that predate the introduction of digital data recording. The material is in analogue form such as film or microfiche.
PC index
The PC-index monitors geomagnetic activity on the Polar Caps. This IAGA-endorsed index consists of two parts: PCN describes activity in the Northern Polar Cap and is determined from magnetic data taken at the geomagnetic observatory Qaanaaq (Thule) in Greenland (+85 degree magnetic latitude) under the responsibility of DTU Space. PCS monitors activity in the Southern Polar Cap and is determined by Arctic and Antarctic Research Institute (AARI). Read more about the PCN index here or at the PC index webpage.
Catalogues (pdf) of the WDC Copenhagen analogue data archive
History
The WDC Copenhagen was established for the International Geophysical Year in 1957 at the Danish Meteorological Institute. The Geomagnetic Data Master Catalogue of hourly and 1-minute means of the geomagnetic observatories was developed at WDC Copenhagen and moved to WDC Edinburgh at BGS in 2007.
The WDC Copenhagen is maintained by DTU Space from 2010 onwards. The WDC Copenhagen is accredited by ICSU World Data System (ICSU-WDS).
PCN index by DTU Space is licensed under the Creative Commons Attribution 4.0 International (CC BY 4.0) .
Kp index and its derivatives by GFZ Potsdam are licensed under the Creative Commons Attribution 4.0 International (CC BY 4.0) .